How to render an overlay on a block on the client-side

I want to make it so I can visually indicate to a player that they are near powdered snow. Some sort of border that could maybe even have CTM compatibility would be nice. This indicator would only be active if a specific (logic) Player Lifetime variable is set to true. 

Could I use this plugin? https://mcreator.net/plugin/93491/custom-fog-plugin-forge-1182-1192

I don't want to install it, just for it not to have the features I'm looking for. I asked the dev, just waiting for a response. But, if someone has already tackled this, I'd love to hear your solution.